Knife sharpener



July 26, 1938. G, HAMMOND 2,124,878

KNIFE. SHARPENER Filed Aug. 6, 1955 Illlllllllllllllm Patented July 26,1938 1.

UNITED STATES PATENT OFFICE KNIFE SHARPENER Grant Hammond, New Haven,Conn.

Application August 6, 1935, Serial No. 34,939

` Claims.

My invention relates to the class of devices for sharpening knives, Yandan object of my invention, among others, is the production of asharpening device for this purpose that shall 5 be simple inconstruction and particularly eiiicient in operation.

One form of a Sharpener embodying my invention and in the constructionand use of which the objects herein Set out, as well as others, may beattained is illustrated in the accompanying drawing in which Figure 1 isa side View of my improved sharpener.

Figure 2 is an end View showing the application of a knife thereto inthe 4Sharpening operation.

Figure 3 is a top View.

Figure 4 is a View in central crosswise section. Figure 5 is a View incentral longitudinal Section.

Figure 6 is a top view showing the operation v of sharpening a knife.

Figure 7 is a detail view on enlarged scale showing the Sharpeners andtheir relative locations.

In the operation of cutting meat, butchers require a knife with anextremely keen edge and at the present time the operation of sharpeninga butcher knife, often by 'grinding requires eX- pert handling. By theuse of my improved sharpening device a keen edge may be applied to abutcher knife without requiring any particular expert qualifications,such lSharpener being shown in the accompanying drawing in which thenumeral 8 denotes the block of my improved Sharpener having a Slot 9extending across it at about its lengthwise center. This slot is for thepurpose of receiving the edge of the knife and also for receiving thematerial removed from Such edge in the Sharpening operation. This blockmay be hollowed out and provided with a chamber I0 if desired, the Slot9 cutting across Such chamber, and as shown in Fig. 5 of the drawing..15 A pair of Sharpeners II is pivotally attached to the block near eachend thereof, and as Shown in Fig. 3 of the drawing, the pivot screws I2passing through ythe Sharpeners near their outer ends. The inner orcutting ends of the Sharpeners are serrated or provided with cuttingteeth I 4 the edges of which are beveled so that they convergedownwardly, as shown in Fig. 1, this convergence providing sharpeningnotches I5 between the meeting edges of the Sharpeners. The teeth I4also intermesh, as

(Cl. 'Y6-86) shown in Fig. 7. The teeth are also formed on a curve, thearc of which is Struck from the center of the pivots I2 so that aS theSharpeners II are rotated on their pivots the teeth will intermesh fromone edge of each cutter or Sharpener to its opposite edge and will alsomaintain the same cutting formation on the cutter irrespective of itsposition. An important feature of the invention resides in thearrangement of the teeth I4 which are formed or extend on the radius ofa circle having the axis of the pivots I2 as their centers.

The Sharpeners are normally yieldingly held in a mid-position as Shownin Fig. 3 of the drawing. In the structure herein shown they are squaredat their outer ends as at I6, and springs Il are secured to the blockpreferably in a 'groove I8 as by means of screws or other suitablefastenings. These springs are of considerable width and press againstthe Squared ends of the In the operation of Sharpening a knife blade 20it is placed in the notch I5 and is then drawn or pushed toward one sideof the block, as Shown in Fig. 6, the springs II exerting a resistanceto Such movement. Under the application of proper pressure thisresistance may be Suicient to permit the blade to move relatively to theSharpeners and at the same time cause them to rotate on their pivots. Alittle practice will enable this action to be acquired. When theSharpeners reach their extreme lateral movement the guides will stopsuch movement and the blade may be drawn or pushed until it is freedfrom the Sharpeners. It will usually be found that two or threeapplications in this manner will suffice to produce an extremely keenedge upon a comparatively dull blade.

It will be understood that the Sharpeners, partieularly as to thecutting ends, will be composed of material of suitable hardness toproduce the cutting results such material, as nitrided steel, beingreadily obtained for the purpose.

By the use of my improved device a butcher may readily produce a verykeen edge upon a butcher knife and with little effort and no particularskill and it will therefore not be required to employ the services of anexpert grinder, as is the practice at the present time, to place aproper edge upon the blade.

In accordance with the provisions of the patent statutes I havedescribed the principles of operation of my invention together with thedevice which I now consider to represent the best embodiment thereof;but I desire to have it understood that the device Shown is onlyillustrative and that the invention may be carried out by other meansand applied to uses other than those above set out.

I claim: y

l. A sharpening device including a block, a sharpener pivotally attachedto said block and having a cutting end movable on said pivot in thedirection of lengthwise sharpening movement of an article during .asharpening operation, means cooperating with said end to support saidarticle for application of pressure thereto, and means for resilientlyresisting pivotal action of said Sharpener during the swingingsharpening movement.

2. A sharpening device including a block, a Sharpener pivotally attachedto said block and having a cutting end movable on said pivot in thedirection of lengthwise Sharpening movement of an article during asharpening operation, means cooperating with said end to support saidarticle for application of pressure thereto, said means and said endhaving cutting teeth, and means for resiliently resisting pivotal actionof said Sharpener during its swinging sharpening movement caused bylengthwise movement of the article between said Sharpener and supportingmeans.

3. A sharpening device including a block, a pair of Sharpeners eachpivotally attached to said block and having a cutting end, the pivotbeing disposed to effect pivotal action of the Sharpeners in thedirection of lengthwise sharpening movement of an article during asharpening operation, cutting elements formed on the ends of saidSharpeners to receive pressure of the article being sharpened, saidSharpeners being shaped to create a notch between them, and means forresiliently resisting pivotal action of said Sharpeners during theirswinging sharpening movement caused by lengthwise movement of Saidarticle between them.

4. A sharpening device including a block, a pair of Sharpeners pivotallyattached to said block and having curved ends provided with cuttingelements to receive pressure of an article being sharpened and tosupport Said article to maintain its Contact with said Sharpeners duringsharpening movements, said pivots being disposed to effect swingingmovement of said Sharpeners in the direction of lengthwise sharpeningmovement of said article during a sharpening operation, and means forresiliently resisting pivotal action of said Sharpeners duringsharpening operations.

5. A sharpening device including a block, a pair of Sharpeners pivotallyattached to said block and having intermeshing toothed ends comprisingcutting elements, said pivots being disposed to effect swinging movementof said ends in the direction of lengthwise sharpening movement of anarticle during a sharpening operation and said ends being shaped to forma notch between them, and means for resiliently resisting pivotal actionof said Sharpeners while permitting swinging pivotal movement thereof.

6. A sharpening device including a block, a pair of Sharpeners pivotallyattached to said block and having squared ends, said pivots beingdisposed to effect swinging movement of said ends in the direction ofsharpening movement of an article during a sharpening operation, andsprings effecting pressure against said squared ends and toward theopposite ends of the sharpeners to hold them in a central position, theopposite ends ofsaid Sharpeners being supplied with cutting elements.

'7. A sharpening device including a block, a pair of Sharpenerspivotally attached at their opposite ends to said block and having theopposite adjacent ends supplied with cutting elements, said cuttingelements being formed on arcs of circles having said pivots as theircenters and said cutting elements intermeshing each with the other,guides for directing reciprocating movement of said Sharpeners, andsprings arranged to resiliently resist movement of said Sharpeners fromtheir central positions with respect to Said lateral movement.

8. A sharpening device including a block, a pair of Sharpeners pivotallyattached at their opposite ends to said block and having the oppositeadjacent ends supplied with cutting elements, said cutting elementsbeing formed on arcs of circles having said pivots as their centers, andsaid cutting elements intermeshing each with the other, ,and springsarranged to resiliently resist movement of said Sharpeners from theircentral positions with respect to lateral movement.

9. A sharpening device including a block, a pair of Sharpeners pivotallyattached at their opposite ends to said block and having the oppositeends supplied with cutting elements, said cutting elements being formedon arcs of circles having said pivots as their centers, guides fordirecting reciprocating movement of the sharpeners, and springs arrangedto resiliently resist movement of said Sharpeners from their centralpositions with respect to lateral movement.

10. A sharpening device including a block, a Sharpener pivotallyattached to Said block on a pivot disposed to effect swinging movementof the cutting end of the Sharpener in the direction of lengthwisesharpening movement of an article during a sharpening operation, SaidSharpener having cutting teeth on said end extending on the radius of anarc having said pivot for its center, means cooperating with Said end toreceive pressure of a blade therebetween during the sharpeningoperation, said Sharpener having a pivotal action during such operationand the teeth being disposed substantially at right angles to thedirection of movement of the article being sharpened, and means forresiliently opposing pivotal action of said Sharpener during thesharpening operation.

GRANT HAMMOND.

